Perennially reservations weird behaviour whilst not configured correctly
Whilst using RDM disks in your environment you might notice long (even extremely long) boot time of your ESXi hosts. That’s because ESXi host uses a different technique to determine if Raw Device Mapped (RDM) LUNs are used for MSCS cluster devices, by introducing a configuration flag to mark each device as perennially reserved that is participating in an MSCS cluster. During the start of an ESXi host, the storage mid-layer attempts to discover all devices presented to an ESXi host…